The study of masking has been a mainstay in auditory research, yet many of its underlying processes elude quantitative description. Using a combination of traditional methodological approaches and newer techniques, which permit examination of the relationship between the characteristics of specific stimulus waveforms and the responses of individual subjects, we attempt to identify the mechanisms that allow an observer to detect one sound in the presence of other interfering sounds. Our previous research, indicating the need to find alternatives to energy detection models of masking, leads to the evaluation of timing-based models and models that assume nonlinear peripheral interactions. Results questioning critical band theory and indicating the importance of across-frequency interactions are extended here by examining the role of central and peripheral factors in the detection of multiple signals and multiple-component signals. Prior conflicting findings on the importance of across-time interactions in masking are further assessed using new approaches to the study of temporal masking and temporal fringe effects. The results of this research will help to specify the nature of processing both within and between spectral/temporal channels. The work will have implications for auditory theory in general, and for the study of auditory pattern analysis and auditory masking in particular.